react

@markitjs/react

React bindings for the @markitjs/core text highlighting engine. Provides a useHighlight hook and a declarative Highlighter component.

Install

npm install @markitjs/react
# or
bun add @markitjs/react
# or
pnpm add @markitjs/react
# or (Yarn — include @markitjs/core explicitly)
yarn add @markitjs/react @markitjs/core

Peer dependencies: React 18+ or 19+, and @markitjs/core (installed automatically by npm 7+, pnpm, and bun; with Yarn, add @markitjs/core explicitly: yarn add @markitjs/react @markitjs/core).

Quick Start

Hook

Next.js App Router: Add "use client" at the top of any file that uses the hook or <Highlighter>.

import { useHighlight } from '@markitjs/react';

function SearchResults({ query }: { query: string }) {
  const ref = useHighlight(query, { caseSensitive: false });

  return (
    <div ref={ref}>
      <p>Content to search and highlight.</p>
    </div>
  );
}

Component

import { Highlighter } from '@markitjs/react';

function App() {
  return (
    <Highlighter term="react" accuracy="exactly">
      <article>
        <p>React is a JavaScript library for building user interfaces.</p>
      </article>
    </Highlighter>
  );
}

API

useHighlight(term, options?)

Returns a ref to attach to the container element.

const ref = useHighlight<HTMLDivElement>(term, {
  // All @markitjs/core options, plus:
  plugins: [], // MarkitPlugin[]
  timing: 'effect', // 'effect' (default) | 'layout'
  contentKey: value, // optional: re-run when content identity changes
});

Option	Type	Description
timing	'effect' | 'layout'	'effect' runs after paint (SSR-safe). 'layout' runs before paint — use with the DOM renderer to avoid a flash of unhighlighted content.
plugins	MarkitPlugin[]	Plugins to register with the core instance.
contentKey	Key | Key[]	When content is dynamic, pass value(s) that change with content so the effect re-runs and re-applies.

All other options are passed through to @markitjs/core's mark() method. For dynamic content (e.g. state or props), pass contentKey so highlights re-apply when content changes and avoid garbled text. See Framework lifecycles for how the React highlight cycle works.

Highlighter

Declarative component that wraps children and highlights matching text.

<Highlighter
  term="search" // string | string[]
  as="div" // Container element tag (default: 'div')
  className="my-class" // Container CSS class
  style={{ padding: 16 }} // Container inline styles
  contentKey={contentId} // optional: for dynamic content
  caseSensitive={false} // Any @markitjs/core option
  renderer="auto"
/>

Safety

The bindings are designed to be safe across React's rendering model:

Concern	How it's handled
StrictMode	Cleanup runs before re-invocation; unmark is idempotent
Concurrent rendering	Effects only run on committed renders
Next.js SSR/hydration	useEffect doesn't run on the server or during hydration
Re-renders	Options are shallow-compared; no work if nothing changed
Unmount	destroy() is called in the effect cleanup

Performance

• Term: A string term is already stable (same value = no extra work). When term is an array, the hook compares by contents, not reference: passing a new array with the same items (e.g. [word1, word2] every render) will not re-run the effect. Optionally use useMemo for the array if you want to avoid that internal comparison.
• Options: Pass a stable options object (e.g. useMemo(() => ({ ... }), [deps]) or a constant) so the effect does not re-run when nothing actually changed. Options are shallow-compared; a new object reference every render may trigger re-runs even when values are the same.

Next.js Usage

The Highlighter component includes a 'use client' directive. Use it inside Client Components:

// app/search/results.tsx
'use client';

import { Highlighter } from '@markitjs/react';

export function Results({ query, html }: { query: string; html: string }) {
  return (
    <Highlighter term={query} renderer="auto">
      <div dangerouslySetInnerHTML={{ __html: html }} />
    </Highlighter>
  );
}

Server Components can render the content; the Highlighter applies highlights client-side after hydration.

Batched Rendering

For large content areas, enable batched rendering to keep the UI responsive:

const ref = useHighlight(query, {
  batchSize: 500,
  done: (count) => setMatchCount(count),
});

CSS Highlight API Styling

When using the default auto renderer on supported browsers, add this CSS:

::highlight(markit-highlight) {
  background-color: #fef08a;
  color: inherit;
}

License

MIT